annandale



UNITED STATES PATENT OFFICE.

JAMES H. ANNANDALE, OF POLTON, COUNTY OF MID-LOTI-IIAN, SCOTLAND.

STEAM-BOILER OR OTHER FURNACE.

SPECIFICATION forming part of Letters Patent No. 411,084, dated September 17, 1889.

Application filed January 24, 1889.

To all whom it may concern.-

Be it known that I, J AMES HUNTER ANNAN- DALE, a subject of the Queen of Great Britain and Ireland, and a resident of Polton, in the county of Mid-Lothian, Scotland, have invented certain Improvements in Steam-Boiler or other Furnaces, of which the following is a specification.

My said invention has for its object, by an improved construction of steam boiler or other furnaces, to secure a large saving in fuel as compared with many existing furnaces, to

prevent smoke,and to very completely exhaust the combustible constituents of the fuel. The improved arrangements are also such as to diminish labor and exposure of the stokers to extremes of heat and cold, while avoiding as much as possible injurious action on the boiler from the admission of chilling aircurrents.

In carrying out my invention I form at the inner end of each furnace a rectangular opening, in which I fit a frame carrying a perforated hearth-slab or a grating, and mounted so that it can be turned about a longitudinal or transverse axis into a vertical or inclined position.

In working with the improved apparatus the fuel is by preference heaped up at the front ends of the fire-bars, and is gradually pushed inward until it reaches the movable frame. WVhen the residue of the fuel at any time upon the movable frame is considered to be sufficiently exhausted, the frame is turned up to drop it into the ash-pit below, from which pit the ashes or residue can be removed at any convenient time. The frame is next turned back to its horizontal position and the fuel on the bars is pushed inward so that a portion of it may be moved onto the frame.

Along with the improvedapparatus hereinbefore described I prefer to use a hollowbridge, into which is led air, which may be either cold or heated by passing through pipes arranged in portions of the dues, the hollow bridge being made with orifices, through which the air issues among the gases passing from the furnace, with the effect of preventing smoke by further promoting complete combustion.-

Serial No. 297,413. (No model.)

In order that my said invention and the manner of performing the same may be properly understood, I hereunto append a sheet of drawings to be hereinafter referred to, and showing, by way of example, the application of my invention to the internal furnace of a horizontal cylindrical steam-boiler of a common type.

Figures 1, 2, and of the drawings are respectively horizontal, longitudinal vertical, and transverse vertical sections as taken through the furnace and boiler.

In the drawings the same reference-letters are used to mark the same or like parts wherever they are repeated.

From the dead-plate A the furnace-space B is for rather more than two-thirds of its length fitted with ordinary fire-bars C, carried in the usual way on the dead-plate A and on crossbearers D E. A space between the inner ends of the fire-bars C and the bridge F is occupied by a grating G, formed with or fixed in a frame, which is made with trunnions J K at the middle of its back and front. The back trunnion J is entered into a bearing in a block fixed in the bridge F, and the front trunnion K projects through the innermost cross-bearer E of the fire-bars C, and at the front of that bearer has coupled to it a spindle L, which extends out beyond the front of the boiler and is supported near its front end by a bracket M. At the front end of the spindle L there is fixed a clutch N, and a lever or bar can be applied to this clutch for the purpose of turning the spindle L and inverting or inclining the movable grating G so as to cause the residue or ashes on it to fall into the ashpit. Catches may be provided to keep the grating G in the horizontal position except when it is being turned to drop the ashes. The bridge F is made hollow and with perforations along its top for the issue of jets of air to complete the combustion of the fuel products, the air being supplied to the interior of the bridge by pipes P, which in this example are led through parts of the boiler-fines in order that the air may be heated on its way to the bridge.

The apparatus hereinbefore described is obviously adaptable without the least diificulty to various kinds of boiler-f urnaces, and

also to various other furnaces, and in all applications it affords extremely simple means, which, with ordinary attention to stoking according to the easily-executed method hereinbefore explained, will result in the fuel being burned in the most economical and advantageous manner, without smoke, and with a minimum of residue or ashes.

I am aware that dumping-grates have been used at the rear ends of ordinary grates; but in my invention the dumping-grate is mounted on a central axis longitudinally of the horizontal fire-bars, and connected to a rotary spindle extending out to the front of the furnace, so that the grate is not only self-balancing, but is comparatively easy to manipulate.

I claim as my invention- The combination of the horizontal or nearly name to this specification in the presence of 30 two subscribing witnesses.

JAS. H. ANNANDALE.

Witnesses:

J. SIMPSON "JACK, Solicitor, Edinburgh.

NEIL BROWNLEE, Clerk, 8 York Build mg, Edinburgh. 

